Two-dimensional (2D) materials have attracted significant attention for device applications due to their
unique structural, electronic and catalytic properties. Here, we have deposited a vertically aligned, highly
ordered Pd decorated MnO2 nanowalls directly on a porous anodic alumina (AAO) by reactive sputtering
and then it used as a gas sensor without additional processing. The nanowalls sensor shows remarkably
high and selective responses to hydrogen gas with low detection range 10–10000 ppm. Our results
demonstrate the potential application of Pd decorated MnO2 nanowalls for fabricating highly sensitive
and selective gas sensors.